Commit 13207f94 authored Jul 13, 2022 by Kuniyuki Iwashima Committed by Greg Kroah-Hartman Jul 29, 2022

tcp/dccp: Fix a data-race around sysctl_tcp_fwmark_accept.



[ Upstream commit 1a0008f9df59451d0a17806c1ee1a19857032fa8 ]

While reading sysctl_tcp_fwmark_accept, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.

Fixes: 84f39b08 ("net: support marking accepting TCP sockets")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent fc92e3b4

include/net/inet_sock.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -113,7 +113,8 @@ static inline struct inet_request_sock inet_rsk(const struct request_sock sk)

		static inline u32 inet_request_mark(const struct sock sk, struct sk_buff skb)
		{
		if (!sk->sk_mark && sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept)
		if (!sk->sk_mark &&
		READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept))
		return skb->mark;

		return sk->sk_mark;